Information display devices

Abstract

A display device of the matrix type utilizes coincident current selection of display elements by the provision of row conductors (R) activating row electromagnets (D) and column conductors (C) activating column electromagnets (H). Each display element includes a rotatable vane (S) which is stable in open and closed positions and a permanent magnet (M) co-operates with the electromagnet (D) to urge the vane (S) into the appropriate position. A clutch member in the form of a bar (L) extending from the vane (S) contacts the pole face of an electromagnetic (H) which, when activated, serves to inhibit movement of the vane irrespective of activation of the row electromagnet (D). Thus by pulsing the display row-by-row, the state of the display elements can be set by selective inhibiting of movement in coincident manner of the appropriate vanes (S) by pulsing the respective column conductors.

I claim: 
     
       1. A display matrix, comprising (a) a generally planar support (1) containing a plurality of display elements;   (b) a plurality of display members (S) rotatably connected with said support associated with said display elements, respectively, said display members being rotatable between first and second positions to alter the appearance of the display elements;   (c) a plurality of permanent magnets (M) connected with said display members, respectively;   (d) first ferromagnetic members (L) connected with said display members, respectively, in spaced relation from said permanent magnets;   (e) actuating means connected with said support for rotating said display members between said first and second positions, said actuating means including (1) second ferromagnetic members (D) arranged adjacent said permanent magnets, respectively, at least when said display members are in said first positions; and   (2) first coil means (R) connected with a group of said second ferromagnetic members to magnetize said group of second ferromagnetic members upon energization of said first coil means to urge rotation of a group of adjacent display members by interaction with the adjacent permanent magnets; and     (f) current controlled holding means connected with said support for selectively retaining display members against rotation in response to said actuating means, said holding means including (1) third ferromagnetic members (H) connected with said support and arranged adjacent said first ferromagnetic members, respectively, at least when said display members are in said first position; and     (2) second coil means (C) connected with a set of said third ferromagnetic members arranged so that selective predetermined energization of said second coil means prevents, by interaction between said set of third ferromagnetic members and adjacent first ferromagnetic members, rotation of selected display members of said group that are urged to rotate by energization of said first coil means.   
     
     
       2. A display matrix as defined in claim 1, wherein said first, second and third ferromagnetic members are of ferromagnetic material of low remanence. 
     
     
       3. A display matrix as defined in claim 1, wherein said first ferromagnetic members are permanent magnets. 
     
     
       4. A display matrix as defined in claim 1, wherein at least one of said first and second coil means comprises several coils spaced apart from each other and connected in series and wherein for each display element said first and third ferromagnetic members are arranged close to each other when the display member is in said first position and remote from each other when the display member is in said second position. 
     
     
       5. A display matrix as defined in claim 4, wherein said first and third ferromagnetic members are of ferromagnetic material of low remanence.